Pin n. 1.A piece of wood, metal, etc., generally cylindrical, used for fastening separate articles together, or as a support by which one article may be suspended from another; a peg; a bolt. "With pins of adamant And chains they made all fast."
2.Especially, a small, pointed and headed piece of brass or other wire (commonly tinned), largely used for fastening clothes, attaching papers, etc.
3.Hence, a thing of small value; a trifle. "He... did not care a pin for her."
4.That which resembles a pin in its form or use; as: (a)A peg in musical instruments, for increasing or relaxing the tension of the strings.
(e)(Mach.) A short shaft, sometimes forming a bolt, a part of which serves as a journal.
(f)(Joinery) The tenon of a dovetail joint.
5.One of a row of pegs in the side of an ancient drinking cup to mark how much each man should drink.
6.The bull's eye, or center, of a target; hence, the center. (Obs.) "The very pin of his heart cleft."
7.Mood; humor. (Obs.) "In merry pin."
9.An ornament, as a brooch or badge, fastened to the clothing by a pin; as, a Masonic pin.
10.The leg; as, to knock one off his pins. (Slang)
Banking pin (Horol.), a pin against which a lever strikes, to limit its motion.
Pin drill (Mech.), a drill with a central pin or projection to enter a hole, for enlarging the hole, or for sinking a recess for the head of a bolt, etc.; a counterbore.
Pin grass. (Bot.) See Alfilaria. Pin hole, a small hole made by a pin; hence, any very small aperture or perforation.
Pin lock, a lock having a cylindrical bolt; a lock in which pins, arranged by the key, are used instead of tumblers.
Pin money, an allowance of money, as that made by a husband to his wife, for private and personal expenditure.
Pin rail (Naut.), a rail, usually within the bulwarks, to hold belaying pins. Sometimes applied to the fife rail. Called also pin rack.
Pin wheel. (a)A contrate wheel in which the cogs are cylindrical pins.
(b)(Fireworks) A small coil which revolves on a common pin and makes a wheel of yellow or colored fire.
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